Polyethers having an aliphatic double bond in molecular chain terminal position, that is, double bond-terminated polyethers, are compounds useful, inter alia, as reactive surfactants for emulsion polymerization, as intermediates for such reactive surfactants, and as intermediates for polysiloxane/polyether copolymers. Japanese Patent No. 2,672,385 (JP 2,672,385 B) discloses a method of producing a polyether having the allyloxy group at one terminal by the addition polymerization of butylene oxide and ethylene oxide on allyl alcohol in the presence of a base catalyst. Japanese Unexamined Patent Application Publication No. 2001-342156 (JP 2001-342156 A) discloses a method of producing an unsaturated aliphatic alcohol/alkylene oxide adduct by the addition polymerization of an alkylene oxide on an unsaturated aliphatic alcohol in the presence of the strong acid salt of a metal. JP 2002-179788 A discloses a method of producing a polyether that has an alkenyl at one terminal and hydroxyl at the other terminal; this method proceeds by the addition polymerization of an alkylene oxide on an unsaturated aliphatic alcohol in the presence of a Lewis acid catalyst or composite metal oxide catalyst. However, the structural unit of these polyethers is limited to the alkyleneoxy group.
JP S62-059236 A discloses a method of producing a polyether having an aliphatic double bond at one molecular chain terminal and hydroxyl group at the other terminal; this method proceeds through the ring-opening polymerization of an alkylene oxide or a glycidyl ether or both in the presence of an aliphatic double bond-containing alcohol and a cationic initiator (for example, a Friedel-Crafts catalyst, protonic acid). JP S62-059236 A also discloses the polyether produced by this method, i.e., polyether having an aliphatic double bond at one molecular chain terminal and hydroxyl group at the other terminal. However, due to secondary reactions that accompany this polymerization, the molecular weight distribution has a broad polydispersity of at least 1.3 to a maximum of 7.5, and only a low-purity polyether is obtained. Low-purity alkenyl-monoterminated polyether with such a broad molecular weight distribution (polydispersity) is unsuitable as a reactive surfactant for emulsion polymerization and is also unsuitable as an intermediate in the production of polyether-modified organopolysiloxanes using the hydrosilylation reaction. It is also unsuitable as an intermediate in the production of block copolymers. Moreover, a polyether having alkenyl at only one terminal is unsuitable as an intermediate for the production of block copolymers. In addition, the oxidation resistance is unsatisfactory when the alkyleneoxy group is the main structural unit.    [Patent Reference 1] JP 2,672,385 B    [Patent Reference 2] JP 2001-342156 A    [Patent Reference 3] JP 2002-179788 A    [Patent Reference 4] JP S62-059236 A